Semiconductor devices are main functional units in an integrated circuit, and various semiconductor devices are essential components for achieving specific functions of the integrated circuit. In order to connect the semiconductor device to an external circuit, normally a through hole is formed on a back surface of a substrate of the semiconductor device to expose a contact pad on a front surface of the substrate. It is required to form an insulating layer in the through hole and a rewiring layer on a surface of the insulating layer. The rewiring layer is connected to the contact pad, and extends to outside of the through hole. The rewiring layer outside of the through hole is connected with a connecting end for connecting with the external circuit.
In the conventional technology, when manufacturing a semiconductor component, the insulating layer is formed in the through hole. The insulating layer at the bottom of the though hole is required to be removed by an etching process so as to expose the contact pad. However, an over-etching problem is prone to occur in the conventional semiconductor devices, resulting in a poor reliability of the semiconductor devices.